Flex sensitive normally closed ribbon switch

ABSTRACT

A normally closed ribbon switch has two conductor strips each having transverse curvature. The strips are mounted to touch on their convex sides. The conductor strips have a pair of insulation strips mounted along and between the outer edges of the conductor strips whereby when the ribbon switch is flexed the strips lose their transverse curvature and the electrical contact between the conductor strips opens.

United States Patent 1 Koenig [54] FLEX SENSITIVE NORMALLY CLOSED RIBBON SWITCH [75] Inventor: Robert H. Koenig, Huntington Hills,

[73] Assignee: Tapeswitch Corporation of America, Farmingdale, N.Y.

[22] Filed: Sept. 14, 1971 [21] Appl. No.: 180,319

[52] US. Cl. ..200/85 R, 200/86 R, 200/166 BH [51] Int. Cl. ..H0lh 1/26, HOlh 3/14 [58] Field of Search .....200/l59 B, 86 R, 85 R, 85 A,

200/166 BI-I, 61.43, 67 DB [56] References Cited UNITED STATES PATENTS 3,553,404 l/l97l Koenig ..200/86 R X 3,619,530 11/1971 DeVincent et a1 ..200/l59 B Feb. 20, 1973 OTHER PUBLICATIONS Snap-Action Membrane Switch Keyboard; IBM Technical Bulletin; Vol. 7, No. 12, May 1965 by R. K. Hayes et al.

Primary Examiner-H. 0. Jones Assistant Examiner-Robert A. Vanderhye Attorney-James P. Malone [57] ABSTRACT A normally closed ribbon switch has two conductor strips each having transverse curvature. The strips are mounted to touch on their convex sides. The conductor strips have a pair of insulation strips mounted along and between the outer edges of the conductor strips whereby when the ribbon switch is flexed the strips lose their transverse curvature and the electrical contact between the conductor strips opens.

2 Claims, 5 Drawing Figures VPA'TEINTEDFEBZOISTS FIG! PIC-:3

FIG 2 If. a/ 4 FIGS INVENTOR.

ROBERT H. KOEN I G FLEX SENSITIVE NORMAILLY CLOSED RIBBON SWITCH This invention relates to ribbon or tape switches and more particularly to normally closed ribbon switches.

This invention is a ribbon or tape switch which opens its circuit when flexed. In relaxed condition it remains closed. The use of the invention is to detect flexing of hose, door hinges, seat cushions, belting, etc. This sensing switch can also detect tension on a belt, hose or cord. Switches made with this design are compact, rugged and can be made sealed from the weather, and they are economical.

Accordingly a principal object of the invention is to provide new and improved ribbon or tape switch means.

Another object of the invention is to provide new and improved normally closed ribbon or tape switch means.

Another object of the invention is to provide new and improved normally closed tape switch means comprising a pair of conductive strips each having transverse curvature, said strips being mounted with their convex sides touching, and a pair of insulating strips mounted along and between the edges of the conductive strips so that when the switch assembly is flexed transverse curvature is lost and the switch opens.

These and other objects of the invention will be apparent in the following specifications and drawings of which,

FIG. 1 is a perspective view of an embodiment of the invention.

FIGS. 2 and?) are sectional views of the embodiment of FIG. 1.

FIG. 4 is a perspective view showing the switch in flexed open position.

FIG. 5 is an end view of FIG. 4.

Referring to the drawings, the invention generally comprises a pair of conductive strips 1 and 2 of springy material each having transverse curvature. The strips are mounted with their convex sides touching so that the electrical circuit between the wires 6 and 'I will be normally closed.

A pair of insulating strips 3 and 4 are mounted along and between the edges of the strips 1 and 2, for instance, they are preferably mounted on the edge of one of the strips. The assembly is preferably held together with an elastic band 5, and would normally be manufactured with an insulating cover not shown in FIG. I.

When the strip assembly is flexed as shown in FIGS. 4 and 5, then the strips l and 2 lose their transverse curvature and become parallel and are separated by the edge mounted insulator strips 3 and 4, which may be continuous or interrupted.

Alternatively, spaced sheets 10 and 11 of paper thin insulating material may be spaced along the interior center of member 1 and 2 of the ribbon switch with sufficient gaps in between to provide conductive contact between the strips 1 and 2 in the area of the bands 5. The operation of this modification is the same as previously described.

FIG. 2 shows a sectional view of FIG. 1 taken through an area occupied by an insulating sheet 10.

FIG. 3 shows a sectional view of FIG. 1 taken through an area not occupied by one of the sheets 10 lllustrating how the resilient band 5 causes the strips 1 and 2 to be normally in contact.

FIG. 5 illustrates a sectional view of FIG. 4 showing the switch in open position and being flexed along its longitudinal axis. FIG. 5 also shows an insulating cover Ill which is preferably resilient and weatherproof. The strip switch may be made in varying lengths.

I claim:

1. A normally closed ribbon switch comprising,

two conductive strips of springy material each having transverse curvature,

said strips being mounted to touch on their convex sides,

and a pair of insulation strips mounted between the outer edges of said conductor strips, spaced paper thin insulator sheets placed between and separating the convex areas of said strips, said sheets being spaced sufficiently so that contact is normally made between the conductive strips in the contacting gap portion between said sheets,

whereby when said ribbon switch is flexed said conductive strips lose their transverse curvature and the switch opens.

2. Apparatus as in claim 1 having a resilient band mounted around said two conductor strips at said contacting gap portion. 

1. A normally closed ribbon switch comprising, two conductive strips of springy material each having transverse curvature, said strips being mounted to touch on their convex sides, and a pair of insulation strips mounted between the outer edges of said conductor strips, spaced paper thin insulator sheets placed between and separating the convex areas of said strips, said sheets being spaced sufficiently so that contact is normally made between the conductive strips in the contacting gap portion between said sheets, whereby when said ribbon switch is flexed said conductive strips lose their transverse curvature and the switch opens.
 1. A normally closed ribbon switch comprising, two conductive strips of springy material each having transverse curvature, said strips being mounted to touch on their convex sides, and a pair of insulation strips mounted between the outer edges of said conductor strips, spaced paper thin insulator sheets placed between and separating the convex areas of said strips, said sheets being spaced sufficiently so that contact is normally made between the conductive strips in the contacting gap portion between said sheets, whereby when said ribbon switch is flexed said conductive strips lose their transverse curvature and the switch opens. 